1. State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun, Jilin 130012, China
2. Key Laboratory of Material Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, Henan 450052, China
3. School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun, Jilin 130013, China